Conventionally, there is known a camera that is provided in a vehicle so as to capture a vicinity of this vehicle. An image captured by this camera is, for example, displayed on a monitor for visibility auxiliary of a driver and used in sensing for detecting white lines on a road, an object approaching the vehicle, etc.
An extraneous matter such as a raindrop, a snowflake, dust, and mud is adhered to a lens of this camera to become an obstacle to the above visibility auxiliary and sensing, in some cases. Therefore, in recent years, there is proposed an extraneous-matter removing apparatus that ejects a compressed air toward the lens of the camera so as to remove the extraneous matter (see Japanese Laid-open Patent Publication No. 2014-037239, for example).
However, the aforementioned conventional technology has room for improvement in ensuring excellent air-compression performance by a simple configuration.
Specifically, in generating compressed air, there exists a case where an intake route as well as an exhaustion route is arranged on a aide of a nozzle for ejecting the compressed air in order to perform a series of cycles including intake and exhaustion, for example.
In this case, there exists a case where an intake valve and an exhaust valve are provided as check valves between a cylinder chamber, in which air is compressed, and the nozzle so as to prevent an extraneous matter other than air from entering therein from a nozzle side. In other words, the case is for preventing the extraneous matter from entering the cylinder chamber so as to prevent a malfunction and ensure the air-compression performance.
However, when the intake valve and the exhaust valve are provided between the cylinder chamber and the nozzle, a mechanism becomes complicated and further a passage resistance of air becomes large, and thus there exists a fear that an ejection force of the compressed air ejected from the nozzle is reduced by a pressure loss in the exhaust valve, for example.